Remove the SVG paint culling optimization

Source/core/paint/SVGForeignObjectPainter.cpp

Index: Source/core/paint/SVGForeignObjectPainter.cpp
diff --git a/Source/core/paint/SVGForeignObjectPainter.cpp b/Source/core/paint/SVGForeignObjectPainter.cpp
index 37e58373264d565e158680c17304a3bd69ac71f6..90aaf3302b71cf55277bce697019a4c70a2f84ea 100644
--- a/Source/core/paint/SVGForeignObjectPainter.cpp
+++ b/Source/core/paint/SVGForeignObjectPainter.cpp
@@ -23,6 +23,12 @@ void SVGForeignObjectPainter::paint(const PaintInfo& paintInfo)
     GraphicsContextStateSaver stateSaver(*childPaintInfo.context);
     childPaintInfo.applyTransform(m_renderSVGForeignObject.localTransform());
 
+    // When transitioning from SVG to HTML painters we need to keep the PaintInfo rect up-to-date
+    // because it can be used for clipping.
+    // FIXME: We need to find an approach that's not O(n^2).
+    const AffineTransform& transform = SVGRenderSupport::transformToRootBorderBox(m_renderSVGForeignObject, m_renderSVGForeignObject.localTransform());

[pdr., 2014/12/15 05:02:21]

How can we cache this from paint invalidation? (similarly for SVGTextPainter)

[fs, 2014/12/15 10:28:16]

Add:

m_cachedRootTransform = paintInvalidationState->svgTransform() *
localTransform();

(w/ checks and fallbacks)

in RenderSVGBlock::invalidateTreeIfNeeded (invalidatePaintIfNeeded might be
better in theory, but the result should be the same none the less...)

May also just say: 48 additional bytes in RenderSVGBlock - ouch!

[pdr., 2014/12/16 06:29:56]

Thank you! This worked a charm.

I'm not /too/ worried about the extra memory since it's only on RenderSVGText
and RenderSVGForeignObject. The hardest case I know of is iWork which, IIRC,
does one text element per word. WDYT?

[fs, 2014/12/16 09:43:55]

I'm not too worried either - let's just hope that we can offset this increase in
size somehow. (Just get used to me complaining every time you add a few bytes to
some datastructure ;-))

+    childPaintInfo.rect = enclosingIntRect(transform.inverse().mapRect(FloatRect(childPaintInfo.rect)));

[fs, 2014/12/15 10:28:16]

One inverse() too many (since transformToRootBorderBox currently returns the
inverse.) I suppose this is the reason for the try-bot failures?

+

[chrishtr, 2014/12/15 16:36:24]

Maybe just use an infinite rect here to turn off culling for HTML subtrees of
SVG?

     if (SVGRenderSupport::isOverflowHidden(&m_renderSVGForeignObject))
         childPaintInfo.context->clip(m_renderSVGForeignObject.viewportRect());